1. Field of the Invention
The present invention relates to a plug-type electric connector coupled to a receptacle connector.
2. Description of the Related Art
An electric connector is used in almost all of electric or electronic instruments. The electric connector usually includes a receptacle connector and a plug-type connector which is plugged in the receptacle connector. For example, as shown in FIG. 12, a plug-type electric connector 30 disclosed in U.S. Pat. No. 6,896,529B2 includes three plug terminals 31a to 31c, a connector housing (hereinafter simply referred to as “housing”) 32, and a cover body 33. The housing 32 accommodates the plug terminals, and the housing 32 is covered with the cover body 33. The housing 32 and the cover body 33 are made of insulating materials.
The housing 32 includes a rectangular solid-shaped body 32a and a U-shaped heads 32b extending from the body 32a. Three plug terminals 31a to 31c are projected with the same length within the U-shaped head 32b. Opposite portions of the U-shaped head 32b include a pair of side pieces 321 and 322, and thin grooves are formed in the side pieces 321, 322 respectively, and lock arms 341, 342 to be engaged with a mating connector (not shown) are accommodated in the grooves. In the three plug terminals 31a to 31c, their front end portion is located in the U-shaped head 32b, and their rear end portion is accommodated in the housing 32 while projecting into the end portion of the body 32a. Electric wire is connected to the rear end portion of each of the plug terminals 31a to 31c. The housing 32 accommodates the plug terminals 31a to 31c and the lock arms 341 and 342, and then the cylindrical cover body 33 is fitted in the body 32a of the housing 32. A push button 33a is formed in one of surfaces of the cover body 33, the lock arms 341 and 342 are lowered to release the engagement with the mating connector by depressing the push button 33a. 
In the electric connector 30, the respective plug terminals 31a to 31c are projected from the U-shaped head 32b of the housing 32. There is also well known an electric connector which plug terminals are accommodated in a housing before coupling to a mating connector. As shown in FIG. 13, this kind of typical electric connector 35 includes a terminal portion 38, a housing 39, and a cover body 40 covering the housing 39. The terminal portion 38 has a coil spring 36 and a plug terminal 37, and the housing 39 accommodates the terminal portion 38. In coupling the electric connector 35 to the mating connector M, the cover body 40 of the connector 30 is pressed against the mating connector M to move the cover body 40 in a Y-direction. The plug terminal 37 is projected from the cover body 40 and brought into contact with a contact C by moving the cover body 40 in the Y-direction. In the electric connector 35, the plug terminal 37 is accommodated in the housing 39 before coupling with the mating connector M, so that the plug terminal 37 never collides with an obstacle.
In the electric connector 30 disclosed in U.S. Pat. No. 6,896,529 B2, the three plug terminals 31a to 31c are positioned within the U-shaped side pieces 321 and 322 of the U-shaped head 32b, and the three plug terminals 31a to 31c are coupled to the mating connector. Before coupling the three plug terminals 31a to 31c to the mating connector, the three plug terminals 31a to 31c are always projected outward although they are located within the U-shaped side pieces. Therefore, the obstacle or the like comes into contact with the projected plug terminal to damage or deform the plug terminal, and the plug terminal might be folded down at worst. Any damage, deformation or the like of the plug terminal causes a failure of connection to the mating connector in good condition. On the contrary, in the conventional electric connector 35, because the plug terminal 37 is covered with the cover body 40, such problems are never caused. However, in the terminal portion 38 of the electric connector 35, because the plug terminal 37 and the spring 36 are individually formed, the number of component items is increased while an assembling work becomes complicated, and it is difficult to stably maintain electric contact between the plug terminal 37 and the spring 36. Further, because the cover body 40 is moved in coupling the electric connector 35 to the mating connector M, a mechanism for moving the cover body 40 is required to complicate the structure of the electric connector 35.
In view of the foregoing, an object of the invention is to provide an electric connector enabling it to protect the plug terminal with a simple structure in which the contact portion of the plug terminal is pushed into the connector housing before the electric connector is coupled to the mating connector.
Another object of the invention is to provide an electric connector which can easily be assembled with the small number of component items by making the plug terminal integrated with the contact portion and the spring usable.